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Biomedical subjects

T Reed

Publications and source records attributed to T Reed.

At least 73 records · Page 4Linked to original sources
PubMed1991

Effects of placentation on selected Type A behaviors in adult males in the National Heart, Lung, and Blood Institute (NHLBI) twin study.

A dermatoglyphic index derived from monozygotic (MZ) twins of known placental type was used to estimate placentation retrospectively in a sample of adult male MZ twins. Examination of behavioral test scores with respect to placentation showed that the within-pair difference of most measures of type A behavior was smaller in presumed monochorionic than presumed dichorionic pairs. Measures of cognitive function and hostility were not related to placental type. Intraclass correlations in the monochorionic subgroup of MZ twins were greater than the correlations reported for the full sample of MZ twins. The trends were strongest for the Adjective Check List scales taken at two different exams 5 years apart and, to a lesser extent, for the Framingham type A scale. Our results are most consistent with greater intrauterine environmental covariance in monochorionic MZ twins as an explanation for inflation of the MZ twin correlation relative to dizygotic (DZ) correlation reported for some type A measures.

Adult↗
PubMed1991

The NHLBI Twin Study: heritability of apolipoprotein A-I, B, and low density lipoprotein subclasses and concordance for lipoprotein(a).

Heritability of plasma apolipoprotein (apo) A-I, apo B, and low density lipoprotein (LDL) subclasses and concordance for lipoprotein(a) excess were assessed in 109 monozygotic (MZ) and 113 dizygotic (DZ) twin pairs participating in the third examination of the National Heart, Lung, and Blood Institute Twin Study. The intraclass correlation coefficient for apo A-I was significantly greater in MZ twins (0.56) than in DZ twins (0.37, P less than 0.05); however, apo A-I showed an unequal distribution in the two groups, with significantly greater total variance in DZ twins. Therefore the among-component estimate of genetic variance was applied, and the results indicated no significant heritability for apo A-I (P = 0.59). MZ and DZ twins had equal apo B variance. The intraclass correlation coefficient for apo B in MZ twins (0.71) was significantly higher than in DZ twins (0.25) (P less than 0.0001), indicating significant heritability for apo B. Plasma apo A-I levels were significantly correlated with alcohol intake (P less than 0.0001), body mass index (BMI, P less than 0.0001), and physical activity, while apo B levels were significantly correlated only with BMI (P less than 0.05). After plasma apo A-I and apo B concentrations were adjusted for all of these variables and for cigarette smoking, the analysis of variance and intraclass correlation coefficients remained virtually unchanged. The LDL type intraclass correlation coefficient was higher in MZ twins (0.58) than in DZ twins (0.32, P less than 0.005); however, greater total variance for this parameter in DZ twins was observed and after applying the among component estimate of genetic variance, no significant heritability of LDL type was observed. After adjustment for covariate effects the conclusions were not changed. Only 8.4% of MZ twin pairs, as compared with 26.7% of DZ twin pairs, were discordant for elevated lipoprotein(a) on gradient gels (P less than 0.0001). Our data indicate that there is a strong heritability for plasma apo B and lipoprotein(a), with only weak evidence for heritability of LDL type or plasma apo A-I levels within this population sample.

Aged↗
PubMed1991

Concordance of ischemic heart disease in the NHLBI twin study after 14-18 years of follow-up.

Morbidity and mortality were assessed in the NHLBI twin study at the end of 1987. Deaths were greater in DZ twins (58/520, 11.2%) than MZ twins (38/508, 7.5%). Ischemic heart disease concordances were 2.3 times higher in MZ pairs and 2.8 times higher in DZ pairs than expected based on the prevalence of ischemic heart disease in the cohort. Family history scores for heart disease, calculated 14-18 years earlier at entry to the study, were significantly higher in DZ pairs where one or both members later developed ischemic heart disease and in corcordant MZ pairs than in twin-pairs without any subsequent heart disease. Concordance rates were not significantly different between MZ and DZ pairs. The results agree with previous suggestions that selection at enlistment into the armed services over 40 years ago, as well as later volunteering for the NHLBI twin study, resulted in a decline in the number of concordant MZ pairs.

Cause of Death↗
PubMed1991

Influence of placentation on high density lipoproteins in adult males: the NHLBI twin study.

Dizygotic (DZ) World War II veteran twins who participated in the National Heart Lung and Blood Institute (NHLBI) Twin Study have been reported to have greater variance than monozygotic (MZ) twins for plasma high-density lipoprotein cholesterol (HDL-C), cholesterol in the low-density fraction of HDL (HDL2-C) and apolipoprotein A-I, a major protein component of HDL. It was hypothesized that a possible source of this difference in zygosity variance could be prenatal environmental influences related to placental type. Dermatoglyphics were used to provide a retrospective index of placental type in a subset of the NHLBI MZ twins aged 59-70. The MZ twins classified as dichorionic were found to have significantly greater within-pair variability than the monochorionic MZ twins for HDL-C, HDL2-C and Apo A-I. These findings indicate that intrauterine environmental influences on HDL are manifest later in life.

Aged↗
PubMed1991

Genetic effects on cardiovascular responses to cold and mental activity in late adulthood.

The purpose of the present investigation was to examine the genetic contributions to cardiovascular reactivity in an adult cohort of male twins. A total of 47 monozygotic (MZ) twin pairs and 54 dizygotic (DZ) twin pairs, aged 59 to 69 years, were laboratory tested at four sites as part of the third examination of the National Heart, Lung, and Blood Institute Twin Study. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were recorded during two tasks, a mental arithmetic task involving serial subtraction and the cold pressor test. Significant cardiovascular responsivity was observed during both tasks as measured by substantial elevations in SBP, DBP, and HR from resting periods to task periods. Heritability estimates were statistically significant for SBP and DBP but not HR levels during pretask baseline periods and during both tasks. Genetic variance was maintained for blood pressure reactivity to the mental arithmetic task after adjustments for baseline and performance. No genetic variance for SBP or DBP reactivity to the cold pressor test was evident.

Aged↗
PubMed1991

Attempted transcervical occlusion of the fallopian tube with the Nd:YAG laser.

A prospective multi-center trial was initiated to test the efficacy and safety of transcervical occlusion of the fallopian tube with the Nd:YAG laser. A multi-center approach was deemed necessary because of the large sample size required to test adequately the effectiveness of sterilization procedures. However, efforts to continue the study as designed were abandoned because, of the 17 subjects completing the study, only four (24%) had bilateral tubal occlusion at the site of laser treatment. We conclude that the hysteroscopic method, as tested, is inadequate to provide permanent sterilization. Modification of the technique or alterations in patient preparation may improve the outcome.

Adult↗
PubMed1991

Hypothesis: association of the critical region of trisomy 18 and 18q2--syndrome with dermatoglyphic findings and a growth suppressor (deleted in colon cancer) locus.

Evidence from the literature is reviewed to suggest that when fingertip dermal ridge patterns in chromosomal deletion syndromes are characteristic of the opposite spectrum of the developmental scale from patterns found in cases trisomic for the same chromosomal region, the association may be a consequence of loci with growth regulatory functions. Evidence is presented that DNA markers at 18q21 should be the first candidate sequences to be used to test this hypothesis in families with fingertip arches segregating in an apparent autosomal dominant fashion.

Cell Transformation, Neoplastic↗
PubMed1991

Estimates of heritability of plasma homocyst(e)ine levels in aging adult male twins.

Plasma homocyst(e)ine level was determined for 96 identical (MZ) and 92 fraternal (DZ) adult male twins aged 59-69. There was no difference in mean between MZ (10.31 nmol/ml) and DZ (10.36 nmol/ml) twins. The intraclass correlation coefficient of the log-transformed homocyst(e)ine level in 43 complete MZ and 39 complete DZ pairs was 0.55 and 0.19, respectively. The MZ correlation was significantly (p less than 0.05) greater than the DZ correlation, suggesting that the level of plasma homocyst(e)ine is genetically influenced.

Aged↗
PubMed1990

Heritability of cognitive performance in aging twins. The National Heart, Lung, and Blood Institute Twin Study.

The genetic contribution to performance on scales designed to measure mild to moderate decrements in cognitive functioning in a population at risk is unknown. In the present analysis, 134 monozygotic and 133 dizygotic male twin pairs (mean age, 63 years) were given three cognitive tests: the Mini-Mental State examination, the Iowa Screening Battery for Mental Decline, and, for comparison, the Digit Symbol Substitution Test from the Wechsler Adult Intelligence Scale. The primary objective of the analysis was to test for a significant heritable component to performance on these measures. A secondary objective was to determine the extent to which shared variance with significant confounders such as education, age, and depression affects the outcome of the heritability analysis. Results indicate that performance on tests intended to measure cognitive decline in the elderly does have a significant genetic component and that these estimates tend to increase after adjustment for covariates. Heritability estimates adjusted for covariates were 30% for the Iowa Screening score, 60% for the Mini-Mental State score, and 67% for the Digit Symbol Substitution score.

Age Factors↗
PubMed1990

Family history of ischemic heart disease with respect to mean twin-pair cholesterol and subsequent ischemic heart disease in the NHLBI twin study.

This study examines the independent and interactive effects of family history scores (FHxS) for the prevalence of ischemic heart disease with plasma lipids and subsequent morbidity and mortality from ischemic heart disease. FHxS were calculated for 514 sets of middle aged male twins who participated in the entry examination of the NHLBI Veteran twin study in 1969-1973. Comparison of the FHxS with the level of plasma total cholesterol and HDL cholesterol (HDLc) paralleled earlier reported findings in young adults; individuals with high total cholesterol in two exams 8-12 years apart had significantly (P less than .01) higher FHxS. The same relationship was noted when using the mean twin-pair cholesterol level at the initial exam when the twins were in their 40s. Using the pair means over two exams as the cotwins aged into their 50s, the association of FHxS with total cholesterol declined and pairs with HDLc persistently in the highest quintile at both exams had significantly (P less than .01) lower FHxS. The changes in the pattern of association of lipid fractions with FHxS with age parallel the reported age decline of total cholesterol as a risk factor for heart disease. Assessment of ischemic heart disease events up to January 1988 revealed a highly significant association (P less than .0001) of later ischemic heart disease events with FHxS. At each level of lipid categorization pairs who later had events had higher FHxS than those without any subsequent heart disease; these differences were significant in all but the low risk lipid groups (low total cholesterol, high HDLc, and low total cholesterol/HDLc ratio). We conclude that FHxS is related to total cholesterol and HDLc but also is an independent predictor of subsequent ischemic heart disease after 14-18 years of follow-up.

Adult↗
PubMed1990

A comparative study of autistic subjects' performance at two levels of visual and cognitive perspective taking.

This study extended previous investigations of autistic subjects' perspective-taking abilities through a within-subjects contrast between two levels each of both visual and cognitive problems with stringent controls against guessing. When compared with normal and mentally retarded subjects', the autistic group's performance supported Baron-Cohen's (1988) hypothesis of a selective deficit for cognitive perspective taking among autistic subjects. Both levels of visual perspective taking demonstrated virtually unimpaired performance for autistic subjects with no significant difference between them and control groups. On the cognitive perspective-taking tasks, however, the performance of the three groups was significantly different, with the vast majority of autistic subjects unable to do even the most basic level of this task. Possible explanations and educational implications were discussed.

Adolescent↗
PubMed1990

The transfer effect of leadup activities.

Previous literature shows that operative laboratory performance can be significantly improved through leadup training where students complete simulated preparations in plastic blocks. Since the task requirements of most fixed prosthodontic preparations seem similar to those of operative dentistry, it may be hypothesized that leadup training utilizing operative-like preparations would facilitate performance in the projects of both courses. The objective of this study was to test that hypothesis. The performance of students who had completed the leadup training nine months earlier was compared with that of randomly selected control groups, with replacement, in a subsequent operative and fixed prosthodontics course. Calibrated raters were unaware of group affiliation of products. Analyses of variance showed that students in the experimental group statistically significantly outperformed those in the control group on the two operative preparations which were most like products completed during the leadup training. There was no such difference for any of the three fixed prosthodontics products. It is concluded that transfer of training is highly specific and that leadup training must simulate the criterion in both its cognitive and motor components, if it is to have a facilitating effect.

Analysis of Variance↗
PubMed1989

An educational booklet diminishes anxiety in parents whose children receive total parenteral nutrition.

A major cause of anxiety in parents of hospitalized children is insufficient information about hospital procedures. In an effort to determine the extent to which parental anxiety could be diminished and knowledge and satisfaction enhanced in regard to total parenteral nutrition (TPN), we developed a booklet that describes the mechanics of TPN administration and related procedures. When informal discussions were held between parents and members of the nutritional support team during four alternating periods (every five to six months), parents of first-time recipients of TPN either did not receive the booklet (period 1, n = 20; period 3, n = 30) or received it (period 2, n = 23; period 4, n = 27). Within one week of TPN initiation, parents in both groups completed the Spielberger State-Trait anxiety scale, an attitude questionnaire, and a quiz on TPN. No differences between groups were found in ethnic background, socioeconomic status, severity of illness, age of children, or route of TPN administration. Predisposition to anxiety was also similar between the groups. In contrast, acute situational anxiety was significantly greater in the group with no booklet than in the booklet group. Parents in the no-booklet group demonstrated less comfort in the care of their children and less knowledge about TPN than did the booklet group. Written information provided to parents decreased their anxiety and increased satisfaction with patient care more successfully than did verbal communication. Such a booklet may reduce parentally induced anxiety in the child and facilitate parent-hospital staff interactions.

Anxiety↗
PubMed1989

The effect of a pattern in palmar interdigital II on a-b ridge count in black and white Down syndrome cases and controls.

An unconfirmed study by Fang (Ph.D. thesis, Univ. of London, 1950) in Britain showed that individuals with Down syndrome had lower total a-b ridge counts in palmar Interdigital area II (ID II) than a group of controls. This study compares 603 white Down syndrome cases and 93 black Down syndrome cases with 668 white and 402 black controls. Our results confirm those of Fang in that the Down syndrome cases in both racial groups had lower total a-b ridge counts than their respective controls. In addition, the black controls and Down syndrome cases had lower a-b ridge counts than their white counterparts. The mean a-b ridge count was significantly lower in individuals with a pattern in ID II compared to individuals without a pattern in ID II in both the Down syndrome and control groups. Some of the lower a-b ridge counts in the Down syndrome samples can be accounted for by the fact that there is an increased frequency of a pattern in ID II in Down syndrome cases. Both Down syndrome and normal individuals who had a pattern unilaterally had a lower than expected a-b ridge count on the contralateral hand that did not have a pattern. There was a tendency also for increased asymmetry in Down syndrome cases with a pattern in ID II.

Analysis of Variance↗
PubMed1989

Lower extremity peripheral vascular disease. Part 1: Scanning electron microscopy.

The surgical loss of the foot or leg is vigorously resisted by podiatrists who are committed to the conservation of limbs at risk because of peripheral vascular disease. Pathologic changes in blood vessels may, however, progress to a point where no other option is available to the patient. This study assesses amputation of the extremities and investigates tissue alterations that can be identified in diseased blood vessels implicated in these circumstances. Gross pathology and scanning electron microscopy are examined in this, the first of a two-part study.

Amputation, Surgical↗